Compound-truss bridge



(No Model.) 3 Sheets-Sheetv 1.

J. SEMMES.

COMPOUND TRUSS BRIDGE. v No. 566,233. Patented Aug. 18, l896.

(No Model.) 3 SheetsSheet 2.

J. H. 'SEIVIMES. GOMPOUND T'RUSS BRIDGE.

No. 566,233. Patented Aug. 18, 1896.

FIG E1- (No Model.) 3 Sheets-Sheet J. H. SBMMES.

COMPOUND TRUSS BRIDGE.

No. 566,233. Patented Aug. 18, 1896,

Noam Pzrzns ccmuow'umo. WASHINGYON n. c.

NITE STATES A'IEN'I Fries.

JOHN HUBERT SEMMES, OF MERIDIAN, MISSISSIPPI.

COMPOUND-=TRUSS BRIDGE.

SPECIFICATION forming part of Letters Patent No. 566,233, dated August 18, 1896.

Application filed May 28, 1895. Serial No. 551,025. (No model.)

To ctZZ whom it may concern.-

Be it known that I, J OHN HUBERT SEMMEs, a citizen of the United States, residing at Me ridian, in the county of Lauderdale and State of Mississippi, have invented a new and useful Truss, to be known as Semmes Oompound Truss, of which the following is a specification.

My invent-ion relates to improvements in compound-truss bridges, and has for its object to provide a new and useful truss for use in the construction of bridges, which truss will be cheap in construction and at the same time very strong and durable.

My invention will be understood by reference to the accompanying drawings, wherein the same parts are indicated by the same letters throughout the several views.

Figure 1 is a side elevation,partly in section, of a bridge, showing the strands or chords of the truss before the vertical slats or bans have been attached. Fig. 2 is a side elevation of the bridge, showing the truss complete, parts being broken away to better illustrate the invention. Fig. 3 is a top plan view of the bridge, parts of the floor thereof being broken away to illustrate the arrangement of the doorsupporting timbers; and Fig. 4 is a central vertical section of the bridge shown in Fig. 3, taken on the line 4 4 in said figure.

My truss is composed of the upper strand or chord A, the lower strand B, and the middle strand H. These three strands are held firmly together at their ends by the use of bolts in any suitable manner common in the construction of truss-bridges, and form an elliptical or parabolic figure.

The rods E are employed for strengthening the truss and holding the chords together.

The floor-supports P are suspended upon links D by pairs of rods or bolts F F, the up per ends of which rods or bolts pass through the lower chord B, as shown most clearly in Fig. 1. These supports are preferably arranged in the form of elliptical figures, but they may be arranged in any other manner, if desired, and the floor-timbers O, to which the floor is nailed or otherwise suitably secured, are similarly laid upon these supports, as shown in Fig. 3.

G G, &c. represent vertical bars, which are rigidly secured at their ends to the upper and lower chords of the truss, and also in the center, where they cross the middle chord l I, they are rigidly secured to this middle chord. These cross-bars may be used only on one side of the truss, if desired, but I prefer to use two sets on each truss, one on either side thereof, as shown in Fig. 3. In a wooden truss these bars may be simply wooden strips or slats of sufficient stifiness and strength, nailed or bolted across the truss to the chords thereof. These cross-bars G act as braces and serve to stiffen the truss, and by their use a very strong and durable truss may be constructed out of very light material, and the construction of such a truss will be quite inexpensive as compared with the usual cost of a truss as hitherto constructed.

In order to further stiffen the truss, I use braces secured to the outside of the truss, as shown in Figs. 3 and 4, in which figures M is a strip nailed or bolted across the vertical bars G where they are fastened to the middle chord and parallel with the said middle chord.

Anumber of laterally-extending strips N are nailed or bolted at one end upon the strip M, and are also nailed or bolted upon the curved strips L and K, which latter strips are bent and seamed at their ends to the ends of the truss-support S, as shown in Fig. 2.

A number of strips or slats O are nailed or bolted at one end to the upper and lower chords A and B and at their opposite ends to the curved strips K, as shown in Figs. 3 and 4. In bridges of a long span these side braces to the truss serve to stiffen the same laterally.

My truss may be made either entirely of metal or entirely of wood, or partly of metal and partly of wood, as may be desired, and it will be seen that a very stiff, strong, and durable structure is obtained.

Having thus described my invention, what I claim, and desire to secure by'Letters Patent of the United States, is

1. In a truss for use in bridge construction, the combination with the curved upper and lower chords A and B, and the straight middle chord H, all bolted together at their ends, and the vertical bars or strips G rigidily secured to each of said chords across both sides of said truss; of the straight strip M secured across the faces of the vertical bars G on the outside of said truss and parallel with said middle chord; curved strips L and K secured at their ends to the ends of said truss; laterally-extending horizontal braces N secured upon said strips M, L and K; and upper and lower diagonal braces O secured to the upper and lower chords A and B, respectively, and to the outer curved strip K, substantially as described.

2. In a truss for use in bridge construction, the combination with the curved upper and lower chords A and B, and the straight middle chord H, all bolted together at their ends, and the vertical bars or strips G rigidly secured to each of said chords across both sides of said truss; of tie-rods E passing vertically through said chords; the straight strip M secured across the faces of the vertical bars G on the outside of said truss and parallel wit-h said middle chord; curved strips L and K secured at their ends to the ends of said truss; laterally-extending horizontal braces N secured upon said strips M, L and K; and upper and lower diagonal braces 0 secured to the upper and lower chords A and B respectively, and to the outer curved strip K, substantially as described.

3. In a truss-bridge, the combination with the two trusses thereof composed of the curved upper and lower chords A and B and the straight middle chord H, all bolted together at their ends, the vertical bars or strips G rigidly secured to each of said chords across both sides of the truss at short intervals, the straight strip M secured across the faces of the vertical bars G on the outside of said truss and parallel with said middle chord, curved strips L and K secured at their ends to the ends of said truss; laterally-extending horizontal braces N secured upon said strips M, L and K, and the upper and lower diagonal braces O secured to the upper and lower chords A and B, respectively, and to the outer curved strip K; of hangers suspended from said truss; elliptical cross-supports for the floor suspended in said hangers; and longitudinal floor-timbers secured upon said cross-supports and arranged in pairs forming a succession of elliptical figures, substantially as described.

JOIIN HUBERT SEMMES.

Vitnesses:

ROBERT E. LEE, JAMES W. MCBEATH. 

